Potassium acid-base considerations

Noncomphance with the infusion of appropriately prescribed fluids also can lead to dehydration. Patients who have SBS complicated by a pancreatic flsmla and severe diarrhea lose considerable potassium and bicarbonate and may develop metabohc acidosis. Patients with severe diarrhea who have an intact colon wiU conserve sodium and chloride, resulting in considerable loss of potassium and bicarbonate and the development of metabolic acidosis. Quantifying fluid losses with particular attention to the sources of loss wiU aid in the acid-base management of these patients (see Chap. 51). 

One gram of 6,7-dihydro-5H-dibenz[c,e] azepine hydrochloride was dissolved in water, made alkaline with concentrated ammonia, and the resultant base extracted twice with benzene. The benzene layers were combined, dried with anhydrous potassium carbonate, and mixed with 0.261 g of allyl bromide at 25°-30°C. The reaction solution became turbid within a few minutes and showed a considerable crystalline deposit after standing 3 A days. The mixture was warmed VA hours on the steam bath in a loosely-stoppered flask, then cooled and filtered. The filtrate was washed twice with water and the benzene layer evaporated at diminished pressure. The liquid residue was dissolved in alcohol, shaken with charcoal and filtered. Addition to the filtrate of 0.3 gram of 85% phosphoric acid in alcohol gave a clear solution which, when seeded and rubbed, yielded 6-allyl-6,7-dihydro-5H-dlbenz[c,e] azepine phosphate, MP about 211°-215°C with decomposition. 

Isomerism of the but-3-enoic acids into the E-but-2-enoic acids is base-catalysed (Table 8.8), whereas the formation of the other isomers indicates the participation of rt-allylnickel complexes in the reaction. Potassium nickel tetracarbonyl is a considerably poorer catalyst, compared with nickel cyanide, whereas nickel sulphate and nickel iodide are ineffective catalysts. 

At this point, consideration was next accorded to proper introduction of the pair of substituents as in 34. As expected, the regiocontrolled introduction of a methyl group proved not to be problematic, and lithium diisopropylamide came to be favored as the base. The p isomer 29 predominted by a factor of 5 1 over the a isomer for the usual steric reasons (Scheme 5). To reach silyl enol ether 31, it was most efficient and practical to react the 29/30 mixture with chlorotrimethylsilane under thermodynamic conditions. This step proved to be critical, as it allowed for implementation of the Lewis acid-catalyzed acetylation of 31 under conditions where the benzyloxy substituent was inert. Equally convenient was the option to transform the modest levels of enol acetate produced competitively back to starting ketone by saponification with methanolic potassium hydroxide. 

With his colleague Louis-Jacques Thenard (1777-1857), Gay-Lussac did considerable work with electrochemistry to produce significant amounts of elemental sodium and potassium, highly reactive and useful substances that were used to isolate and discover the element boron. Gay-Lussac also completed extensive studies of acids and bases and was the first to deduce that there were binary (two element) acids such as hydrochloric acid (HC1) in addition to the known oxygen-containing acids like sulfuric acid (H2S04). Additionally, he was able to determine the chemical composition of prussic acid to be hydrocyanic acid (HCN) and was considered the foremost practitioner of organic analysis. 

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